


Out of all the stars here

by Sin_Cognito



Category: Undertale (Video Game)
Genre: Alternate Universe - Outertale, Alternate Universe - Underfell, Fluff, M/M, Underfell Sans, fluffyyyyy, mention of all kind of undertale characters, very very fluff
Language: English
Status: Completed
Published: 2017-12-28
Updated: 2017-12-31
Packaged: 2019-02-23 06:38:32
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 3,508
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/13184445
Author URL: https://archiveofourown.org/users/Sin_Cognito/pseuds/Sin_Cognito
Summary: Sans and Red have a common love for the sky. And for each other.





	1. you're the one I love the most

**Author's Note:**

> From a tumblr request I received ages ago :  
> Hi, I have a request. A kustard fic we're they go on a date in outertale , with the quote " Out of all the stars here, you're the one I love the most" or " You're the one that shines the brightest". Thanks

Their one year together anniversary had to be something special. They had celebrated their shared birthday their own way, that is to say on the couch with bottles of ketchup and mustard, but Red really wanted to offer something unique to Sans for their anniversary. It may have sounded sappy to others, especially coming from him, but he didn't care. He had asked Sans out one year ago, so he had to make sure today would be as perfect as possible. He had thought about many ways to make a date perfect, had borrowed Boss' dating manual, had even asked Papyrus for advice... And despite his general anxiety about everything, he was quite confident Sans would enjoy what he had prepared.

The rumbling of the universal machine drew him out of his thoughts and he sighed in relief when he finally saw the short silhouette of his lover. He was pleased to see Sans had 'dressed up' a bit for the occasion : the other's usual striped shorts had been replaced by more elegant but still casual black slacks and he was wearing a simple white shirt instead of his dirty tee under his blue jacket. Red was by no mean disappointed in the last piece of garment. It was old and in a rough shape, but it suited Sans so much it was difficult to imagine him without. And Red loved how the color complimented the other's magic.

Red jumped down from the dusty desk he had been sitting on while waiting for Sans to arrive to hug his lover, who slipped his arms around Red's broader frame to return the hug. Red inhaled Sans' smell. Did the other go as far as to put some perfume, or was he just too much in love with him ? Either way he didn't care.

"so where are we going ?" Sans asked, backing out so he could see Red's face.

"d'you really think im gonna spill the beans that easily ? we're going to outertale," Red answered, earning a cute chuckle from the other skeleton. "fuck did you just make me spill the beans ? aah your magic is too powerful," he added in a dramatic tone, with the back of his hand on his forehead.

"outertale ? we don't go there often," Sans replied, not even hiding the fact he was glad they weren't going to have their date in Underfell. Red's world was dangerous, even for monsters that were used to it like Red and his brother, so he could only understand Sans didn't want to spend too much time in it. There was always an underlying feeling of uneasiness and danger, wherever you went. Finding peace here was too difficult, and that was why Red didn't even consider having their date here. And he didn't want to go to Undertale either because that was Sans' universe and he knew every part of it. Red wanted to surprise Sans.

"okay let's go," Red took Sans' hand and typed the Outertale coordinates on the machine. Several bips and a loading after, and they were crossing the magical door that linked every universe together.

When they arrived, they were welcome by the Sans and Papyrus native from the Outertale universe. They briefly exchanged salutations and once Red was given the key to the house, the other two were on their way to spend the evening with the original Papyrus in Undertale.

Red and Sans were left alone in the basement. Red teleported them to the kitchen to grab their lunch he had prepared beforehand, and in no time they were out of the house, eyes glued to the 'sky'.

Even in Outertale, they knew it was only the ceiling of the cavern, but the rock in this universe had the particularity to be way more reflective of the outside light. The result was a practically perfect reflection of the sky from the surface. During the day however there was so much light that they actually had to dampen the lightness with what they called here 'luminosity magic', which was pretty much the same magic that made snow fall in Snowdin and rain fall in Waterfall. But once the sun set on the surface...

Every wall from the cave illuminated with thousands of reflections of colors, stars or miscellaneous lights from the human villages and town surrounding Mount Ebott. A colorful canvas appeared on the ceiling and never ceased to impress the monsters living trapped under the mountain.

It wasn't the first time Red and Sans had seen the show, but it always was a wonder to look at, the false stars and nebulae different each day. Being two astronomy nerds, they enjoyed pointing at strange constellations and making up stupid names as they went further into the cave. Sans, as the most knowledgeable of the two about sky phenomenons, sometimes explained how things worked in space, how stars were born and how they died, and told Red about all kind of celestial bodies. Red was always enraptured by Sans' stories and explanations, lapping up every word.

Lost in their conversation, they didn't realise they had already walked all the way to the entrance of Waterfall. Red guided his lover further in the meandering paths of the darker cave. He had mapped out the area with his alternate from Outertale to find the best place in the cavern. And that was where he was leading Sans.

They walked around, taking their time in discovering the familiar yet unusual place, whispering bad puns to the echo flowers and marvelling when the words were repeated and echoed in an infinity of reverberations, the voices distorted in a chorus of a thousand voices. Here, everything was more : more beautiful, more magical, more eerie, more quiet... It was like someone had put a contrasting lens over the world and turned the setting at max for every sensation.

Red finally spotted the entrance of the cave he had decided they would have their date in. He stopped and explained Sans he wanted the surprise to be complete.

"so can you put on this blindfold for me sweetheart ?" his voice was a bit hushed, so as not to disturb the quietness of the place. He handed Sans a black piece of fabric and helped him put it on when the other agreed. He then guided carefully his lover into the cavern, warning him for any bump in the path. It wouldn't do for Sans to fall now and hurt himself.

The little tunnel opened on a more spacious cavern, some echo flowers glowing softly on the side, and a beautiful pond in the middle. Only their breath and the sound of water dropping from somewhere could be heard here, the hidden spot too far from the main road.

Red gently pushed Sans near the edge of the water and put their lunch down so that he could undress. Once his clothes were discarded in a messy pile to the side, he leaned over Sans' shoulder and murmured next to his auditory meatus.

"Sans, im gonna undress you know. there's nobody around. just you and me," Red reassured Sans, who he knew was very self-concious about his body. Which was absolutely perfect if you asked Red's opinion. But he knew it was hard sometimes for Sans to show his naked body, so he respected his lover's need for time to prepare mentally. When the other finally hushed a quiet 'okay', he delicately removed the blue jacket, then the white shirt, and finally the black slacks. Sans stood perfectly naked in front of the pond. Red hugged him from the back again, pressing his ribcage against the other's spine. He waited patiently to see if Sans was okay.

"such a shame though," the smaller skeleton finally said, no sign of real tension in his voice.

"what is sweetheart ?"

"i dressed up for you you know."

"are you really gonna tell me you don't like it when i undress you ?" Red huffed, a smile tugging at his teeth.

"heh. touché."

Red entered the basin first, testing the temperature and finding it to be quite warm, despite the relatively chilly air of the cavern. He then took Sans' hand and slowly guided him in the water to the center of the pond.

He lifted his hand and brushed Sans' cheek, who flinched out of reflex. He caressed the bone tenderly and pressed a light kiss on the other's lips. He felt Sans completely relax and went to untangle the knot of the blindfold.

When Sans opened his eyes, what he saw made his jaw drop open. Red even saw blue magic well up in his lover's sparkling eyes.

Red and Sans were hips deep in the pond, the water reflecting the ceiling perfectly. There was darkness and stars and northern lights everywhere around them. The water was so dark and it reflected only the night sky from the surface... It looked like the two monsters were floating in space. They were surrounded by shimmering stars and brightening suns, dark nebulae and somber auroras... Their two silhouettes stood out in the underground galaxy, and there wasn't one centimeter that wasn't worth looking at in the cavern.

And yet... Red couldn't detach his eyes from Sans...

"sans," Red whispered, voice trembling with emotion, "i brought you here today to remind you how much i love you. you mean a lot to me. i know i'm not perfect but i truly love you and want you to know i feel blessed to date you."

He leaned forward so that their forehead touched and lowered his voice even more.

"one day we'll be out of this prison. we'll be free. it's not much but for the time being, i offer you this view of the sky i know you love so much. one day we'll see the real one, and you'll tell me everything that you know about it. i want to be there with you. to share this instant with you."

It took a moment for Sans to say anything, and when he did, he voice was shaking with emotion.

"thank you red. i'm so lucky to have met you. this place is truly beautiful. but you know..." Sans drew back a bit so that he could look at Red's eyes. His next words weren't as shaking as before.

 

" _out of all the stars here, you're the one i love the most_."


	2. you're the one that shines the brightest

Sans was finishing packing everything he needed for his date with Red when he heard the hum of the machine, indicating that his boyfriend had successfully arrived. He lifted his head up from his stuff to hug his slightly taller lover, clanking their teeth in a light kiss while he was at it. Red instantly tightened the hug, locking Sans in place and deepened the kiss into a more heated make-out that left both of them panting for more. Sans hadn't seen Red in the past week, and they had missed each other a lot. Sans was more than relieved to finally be able to hug Red again and feel his warmth next to him. So he let himself soak in the moment a bit longer, even though he knew there wasn't that much time before tonight's main event.

The week had been even more difficult because something drastic had happened. Something that had changed the Underground and the fate of Monsterkind forever.

A human had fallen.

The last soul. A little child with a blue sweatshirt with pinkish stripes, and a red SOUL full of determination. Sans had watched their journey through the Underground, even helping them, until they had finally freed them all. Frisk had befriended every monster they had crossed path with, went to meet the King and broke the barrier. That was what every monster had witnessed, what would be written in monster history books.

But Sans remembered another version. A version where all his friends, all the monsters he knew had tried to kill the child. And where they had sometimes succeeded. He hadn't told anyone about time repeating itself when the child had died. He had shouldered everything, like he always did. He had lied to his brother. He didn't want to worry anyone, and it was only bothersome that time repeated itself. It wasn't like anyone was in real danger, what with Frisk being a pacifist human child. They never harmed nor hurt anyone. Even spared a training puppet, Sans had learnt afterward.

And Frisk had set them free. After a fight with the fallen prince, though Sans didn't remember clearly what happened, they had destroyed the barrier that had kept monsterkind trapped under the mountain for more than a thousand years. Papyrus had seen the sun. So it wasn't a big deal that everything had only lasted 4 or 5 hours, while for Sans it had been more than a week. Everyone was free, Papyrus was happy, Sans had finally met the old lady, everyone had moved to the surface, end of story.

The only downside to all of this had been when he had discovered the machine in the basement didn't work while Frisk was underground. So he hadn't been able to see or hear from Red for a week, though it was only a few hours in real time, and it had been tough. As soon as the barrier was broken though, the machine had bipped familiarly and the link between their world was restored. Red had immediately come and had told Sans there was a human in his world as well. It turned out all the monsters in Underfell had attacked the child too, but apparently they had dealt much more damage than in Sans' world. As Red experienced the resets too, he had explained the child had been killed a countless number of times. For Sans it had lasted a mere 10 days or so, but Red had been trapped in the timeloop for more than 4 months...

As relieved as Sans was to be able to comfort his exhausted lover, he didn't understand why the human in Red's world hadn't broken the barrier... As soon as the thought occurred to him, he found the answer : in Undertale, Asgore was as kind and generous a king as he was evil and egoist in Underfell. So maybe... It hurt Sans to even think it could be true, but he was sure the king in Underfell had used the human's SOUL to escape. By himself. It would explain why the machine worked again, and why Red hadn't experienced any more resets...

Sans couldn't tell Red the truth. But he couldn't pretend to be still trapped underground while the surface awaited them. He decided to make a surprise date for Red, to cheer him up, and after that he would tell him to bring his brother to live on the surface with them, to give them time to find a way to break the barrier in Red's world. As dangerous and unwelcoming as it was, it was still the world in which Red ans his brother had lived all their life after all.

So only two days after Sans had moved to the surface, he had asked Red to come to his world for a date. Red had been a bit surprised for Sans to take the lead, but he had eagerly agreed nonetheless. Sans had made sure that upon his arrival in Undertale, Red wouldn't find out about the present situation of the underground so he had left the basement untouched, while all the furniture in the main house had been moved to the surface.

"so its my turn to make you wear this blindfold red," he told his lover.

"wow, you're really into it huh ?" the other jokingly replied.

As soon as Red put the blindfold over his eyesockets, Sans took his hand and teleported them directly to the castle, in the room where the barrier once had been. It was still moving to Sans to see now an opening to the outside world where there had been the terrible wall of magic trapping monsterkind for a thousand years. He was reminded that Red couldn't see the results of Frisk's determination by a gentle squeeze of the hand.

"what's wrong sweetheart ?"

"nothing red. i just hope you'll enjoy today's date."

"doncha worry about me. as long as i can be with you, i dont care what we do," Red answered, blushing slightly.

"even if i tell you we're going to spend the day cleaning alphys' lab ?" Sans joked.

"you wouldnt be here it it were the case," the other instantly replied.

"touché. yet again."

Sans smiled. Red's witty remarks always cheered him up. They continued walking and soon, they were outside, a beautiful sunset on display before them. Sans almost slipped up and was about to say out loud how beautiful it was. But no, he had decided Red wouldn't see anything from the surface before nightfall. Sans felt a bit bad to prevent Red from seeing the surface he had dreamt about so much, but he had promised Red...

Sans placed Red's hands on his shoulders and they walked towards the top of the nearest hill in a bratty line. As night began to settle, there was nobody to interrupt them so they reached the hill pretty quickly. Sans placed a huge towel on the ground, sat down and guided Red to do the same. When both of them were lying down, Sans gently intertwinded his fingers with Red and put his head on the other's shoulder.

"you can remove the blindfold red," Sans quietly said.

Red did as he was told and when he opened his eyesockets, all he could see was a pitch black ceiling with white pinpricks here and there and... a huge blueish... ball ?

Sans saw him turn his head left and right, a confused expression on his face.

"are we... in outertale ?"

"no."

"this is not waterfall either, so... where are we sans ?"

Just as Red's question was hushed, something moved in the ceiling. A white pinprick ran from left to right, leaving a shimmering silver trail behind.

"this is called a shooting star," Sans softly spoke. "it occurs when a meteoroid enters the atmosphere of the earth. it's also known as a meteor."

"sans... where... are w-we ?" Red's voice caught up in his throat.

"we're on the surface, red. we did it. we're free."

When Red began to sob openly, Sans hugged his lover tight, gently caressing his spine, soothing him until he stopped crying and only sniffed now and then. He could feel confused feelings echoing from Red's SOUL. Happiness, relief and hope mixed up with fear and disappointment. Sans then told him what had happened in the Underground with Frisk, and how he thought that the King from Underfell had fled, leaving the rest of the monsters still trapped. He promised Red they would try everything they could to free the monsters from Red's world as well, that with Frisk's determination nothing was impossible. That soon, everyone would be able to admire the sky, the real sky. The sun, the stars, clouds and real rain... and dustless snow...

It seemed like Red couldn't stop from hugging Sans, his head buried in Sans' chest. He had stopped crying and Sans could see a huge smile on his lover's face.

"hey stop hugging me. you're missing the meteor shower !" Sans said, a smile tugging at his lips.

"i can't stop ! i love you sans !" Red happily cried, crushing Sans in his hug.

Everything fell silent again. Sans gently caressed Red's skull. The gruff skeleton readjusted his position so that he was half lying on Sans and half facing the night sky. They were captivated by all the shooting stars running accross the firmament. Red lifted an arm toward the sky and spread his fingers, as if to catch the falling lights before they'd disappeared.

"it's so far away. and yet it's here, in front of me. i... i can't believe it's the real one."

"i'll bring my telescope next time we come here," sans said.

"how is it possible that it's not as colorful as the lights in Waterfall in Outertale, not as bright, not as pretty, and yet so much more beautiful than everything i've ever known ?" Red questioned to himself. "why am i so blinded by those tiny specks of light that I wanna cry ? what should i do with all this happiness ?"

Sans turned on his side so that he could hug his lover again and whispered, "you deserve it red. you've fought so well, you deserve a break. so for now, just enjoy the view."

Red then turned his head as well and locked gaze with Sans.

"red what are you doing ? you can't see the stars like this."

"i'm doing what you told me. i'm enjoying the view," Red said, wiggling the archs of his eyebrows. "and i swear i'm not wasting anything here, because..."

Red tenderly caressed Sans' cheek.

" _out of all the stars here you're the one that shines the brightest._ "

**Notes for the Chapter:**

> The sequel no one asked but I couldn't decide which sentence I liked the most in the request, so I ended up writing both.


End file.
